Polishing jig air injection apparatus and method

ABSTRACT

This invention discloses a polishing jig air injection apparatus including a polishing jig installation base including a surface on which a spectacle lens polishing jig is placed, an injection member which is inserted into an air injection port of the spectacle lens polishing jig, and an air supply device which supplies the air into a balloon member of the spectacle lens polishing jig via the injection member and the air injection port. The injection member includes a main body formed in a pillar shape, and a seal member. The main body includes an air passage, and an annular groove formed in the outer circumferential portion of the main body. The seal member is inserted into the annular groove, is formed in an annular shape, and uses an elastic body. The seal member has an outer diameter larger than the inner diameter of the air injection port.

BACKGROUND OF THE INVENTION

The present invention relates to a polishing jig air injection apparatusand method for injecting air into a polishing jig provided with aballoon member which inflates by the air pressure.

As a polishing apparatus for polishing the surface of a spectacle lens,a polishing apparatus which uses a polishing jig provided with a balloonmember which inflates by the air pressure is available, as described in,for example, Japanese Patent Laid-Open No. 2004-106117 (literature 1).The polishing jig disclosed in literature 1 includes, for example, aballoon member, a support member which supports the balloon member, anda valve which opens/closes an air passage formed in the support member.

The air passage is formed to extend from an air injection port whichopens on one end surface of the support member into the balloon member.The valve has a structure which opens by the pressure of air suppliedinto the air injection port.

The air is injected into the balloon member while the polishing jig ismounted in an air injection apparatus. The air injection apparatusincludes, for example, an installation base on which the polishing jigis mounted, an injection member inserted into the air injection port,and an air supply device used to discharge air from the air dischargeport of the injection member into the air injection port.

The injection member is attached to the installation base whileprojecting from it so as to be inserted into the air injection port bymounting the polishing jig on the installation base. The injectionmember includes a main body formed in a disk shape, and a seal memberused to seal the gap between the main body and the air injection port.The air discharge port opens on the outer circumferential surface of themain body. The seal member is formed using an elastic material to have acup shape which surrounds the outer circumferential portion of the mainbody so that it is held on the main body by its self elasticity.

Upon discharging air from the air discharge port of the main body intothe air injection port while the seal member is inserted in the airinjection port, together with the main body, the outer circumferentialportion of the seal member inflates outwards in the radial direction andcomes into tight contact with the wall surface of the air injectionport. The seal member thus deforms, thereby sealing the gap between theinjection member and the air injection port. The air discharged from theair discharge port flows into the air injection port from the centralportion of the seal member upon passing through the gap between the mainbody and the seal member.

That is, a polishing jig air injection method related to the presentinvention is performed by a step of supplying air into the injectionmember while it is inserted in the air injection port, and a step ofinflating the seal member outwards in the radial direction by the air.

Unfortunately, in the apparatus and method disclosed in literature 1,air needs to be passed through the gap between the seal member and themain body of the injection member, so the shape of the seal member has agiven constraint. That is, the seal member must be formed in a shape tocover the main body of the injection member, and therefore inevitablyuses a dedicated component with a special shape. This leads to anincrease in manufacturing cost of the air injection apparatus used toinject air into the polishing jig.

Also, when, for example, the seal member deteriorates after it has beenused for a long period of time, its force for clamping the main body mayweaken. When this happens, the seal member easily falls off the mainbody of the injection member. When, for example, the polishing jig isdetached from the air injection apparatus after completion of airinjection, the seal member may fall off the main body of the injectionmember while it is still attached to the air injection port. If the sealmember falls off the main body, an operation of loading the polishingjig into the polishing apparatus is interrupted, thus degrading thepolishing efficiency.

Note that degradation in seal performance of the seal member must beavoided in solving the above-mentioned trouble.

SUMMARY OF THE INVENTION

The present invention has been made to overcome the above-mentionedproblem, and has as its object to provide a polishing jig air injectionapparatus and method which use a seal member that has high sealperformance, and does not easily fall off the main body of an injectionmember, but nonetheless is inexpensive.

According to an aspect of the present invention, there is provided apolishing jig air injection apparatus comprising a polishing jiginstallation base including an installation surface on which a spectaclelens polishing jig including an air injection port and a balloon memberwhich inflates by a pressure of air supplied from the air injection portis placed, an injection member which is supported on the installationsurface of the polishing jig installation base while projecting from theinstallation surface, and inserted into the air injection port of thespectacle lens polishing jig, and an air supply device which isconnected to the injection member and supplies the air into the balloonmember via the injection member and the air injection port, theinjection member including a main body formed in a pillar shape, themain body including an air passage extending through two ends of themain body, and an annular groove formed in an outer circumferentialportion of the main body, and a seal member which is inserted into theannular groove, is formed in an annular shape that extends over anentire circumference along the annular groove, and uses an elastic body,the seal member having an outer diameter larger than an inner diameterof the air injection port.

According to another aspect of the present invention, there is provideda polishing jig air injection method comprising the steps of insertingan injection member into an air injection port of a spectacle lenspolishing jig, and discharging air from the injection member into theair injection port to inflate a balloon member connected to the airinjection port, the injection member including a main body formed in apillar shape, the main body including an air passage extending throughtwo ends of the main body, and an annular groove formed in an outercircumferential portion of the main body, and a seal member which isinserted into the annular groove, is formed in an annular shape thatextends over an entire circumference along the annular groove, and usesan elastic body, the seal member having an outer diameter larger than aninner diameter of the air injection port.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing the arrangement of a polishing jigand installation base;

FIG. 2 is an enlarged sectional view showing an air injection port inthe polishing jig;

FIG. 3 is a sectional view of an injection member attached to theinstallation base;

FIG. 4 is a sectional view showing the state in which the injectionmember is inserted in the air injection port;

FIG. 5 is a sectional view showing another embodiment of an injectionmember;

FIG. 6 is a sectional view showing the state in which the injectionmember is inserted in an air injection port;

FIG. 7 is a sectional view showing another embodiment of an injectionmember;

FIG. 8 is a sectional view showing the state in which the injectionmember is inserted in an air injection port;

FIG. 9 is a sectional view of an injection member attached to aninstallation base;

FIG. 10 is a sectional view showing the initial state of a connectionstep;

FIG. 11 is a sectional view showing the end state of the connectionstep;

FIG. 12 is a flowchart for explaining a method of injecting air into apolishing jig;

FIG. 13 is a sectional view showing the initial state of a connectionstep;

FIG. 14 is a sectional view showing the end state of the connectionstep;

FIG. 15 is a flowchart for explaining a method of injecting air into apolishing jig;

FIG. 16 is a sectional view showing the initial state of a connectionstep;

FIG. 17 is a sectional view showing the end state of the connectionstep;

FIG. 18 is a flowchart for explaining a method of injecting air into apolishing jig; and

FIG. 19 is a sectional view showing the size of each portion in anexperiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

An embodiment of a polishing jig air injection apparatus according tothe present invention will be described in detail below with referenceto FIGS. 1 to 4.

A polishing jig air injection apparatus 1 shown in FIG. 1 includes apolishing jig installation base 3 on which a spectacle lens polishingjig 2 is mounted, an injection member 4 which projects from theinstallation base 3, and an air supply device 6 connected to theinjection member 4 via an air passage 5.

The polishing jig 2 is equivalent to that described in literature 1, andis loaded into a polishing apparatus (not shown) after air is injectedinto it by the air injection apparatus 1 according to this embodiment.The polishing jig 2 according to this embodiment includes a rubberballoon member 11 which inflates by the air pressure, and a supportmember 12 used to support the balloon member 11. The balloon member 11inflates upon being supplied with air from the air supply device 6 (tobe described later), and mounts a polishing pad (not shown) while itssurface is inflated to have a predetermined curvature. The predeterminedcurvature means herein the curvature of the surface of a spectacle lensto be polished.

An air passage 13 used to inject air into the balloon member 11 ordischarge the air from the interior of the balloon member 11 is formedin the support member 12. The air passage 13 includes a circular hole 14which is formed in the support member 12 and has a circularcross-section, and a valve 15 provided between the circular hole 14 andthe balloon member 11. One end of the circular hole 14, which ispositioned on the opposite side of the balloon member 11, opens on aflat attachment surface 12 a of the support member 12 so as to serve asan air injection port 16. The air injection port 16 is formed to open onthe attachment surface 12 a in a circular opening shape and extend in adirection perpendicular to the attachment surface 12 a.

The valve 15 includes a check valve 23 including a ball 21 and conicalcoil spring 22, and an exhaust mechanism 25 including an exhaust pin 24opposed to the ball 21, as shown in FIG. 2. The check valve 23 adopts astructure which passes air from the air injection port 16 into only theballoon member 11. The exhaust pin 24 is used to press the ball 21against the spring force of the conical coil spring 22. The exhaust pin24 is supported by a valve housing 26 to be extendable/retractablebetween a retraction position shown in FIG. 2 and an exhaust position atwhich the leading end of the exhaust pin 24 presses the ball 21. Also,the exhaust pin 24 is biased in a direction away from the ball 21 by aconical coil spring 27 provided between it and the valve housing 26.

The installation base 3 is formed in a plate shape having a flatinstallation surface 3 a on which the polishing jig 2 is mounted, asshown in FIG. 1. Also, the installation base 3 is supported by a movingdevice (not shown) to be movable between a height measurement position(not shown) and a jig attachment/detachment position at which thepolishing jig is attached/detached. The height measurement position is aposition at which a height measuring device (not shown) measures theheight of the balloon member 11 inflated by the air pressure.

The balloon member 11 inflates upon being supplied with air from the airsupply device 6 (to be described later) while it is mounted on theinstallation base 3. The curvature of the surface of the balloon member11 changes in correspondence with the height of the balloon member 11.Therefore, the air is supplied into the balloon member 11 until theheight measured by the height measuring device coincides with thatcorresponding to a target curvature (the curvature of the surface of aspectacle lens to be polished).

The injection member 4 includes a columnar-shaped main body 33 and sealmember 34, as shown in FIG. 3. The main body 33 projects from theinstallation surface 3 a, and includes a threaded portion 32 which isthreadably mounted in a screw hole 31 in the installation base 3. Theseal member 34 is formed from an elastic body and mounted on the outercircumferential portion of the main body 33.

The threaded portion 32 is connected to the air supply device 6 via theair passage 5. The air supply device 6 uses an air compressor (notshown) as an air supply source.

The columnar-shaped main body 33 is formed to have an outer diameter Asmaller than an inner diameter B (see FIG. 2) of the air injection port16 of the polishing jig 2. A through hole (air passage) 35 extendingthrough the two ends of the main body 33 is formed at the axis center ofthe main body 33. The through hole 35 has its one end which opens on theprojection-side end face of the main body 33 as an air discharge port36. The through hole 35 has its other end connected to the air passage5.

An annular groove 41 used to hold the seal member 34 (to be describedlater) is formed in the outer circumferential portion of the main body33 to extend circumferentially. The annular groove 41 according to thisembodiment is formed from a circumferential wall 42 parallel to an outercircumferential surface 33 a of the main body 33, and a first side wall43 and second side wall 44 which extend from the circumferential wall 42outwards in the radial direction. The first side wall 43 and second sidewall 44 are formed parallel to the installation surface 3 a of theinstallation base 3.

The seal member 34 is formed from an elastic body and inserted in theannular groove 41. The seal member 34 has an annular shape which extendsover the entire circumference along the annular groove 41. The sealmember 34 used in this embodiment is a ready-made O-ring.

The seal member 34 is formed to have an inner diameter d1 equal to anouter diameter D of the circumferential wall 42. Also, the seal member34 is formed to have a thickness W smaller than a groove width (aninterval between the first side wall 43 and the second side wall 44) Gof the annular groove 41. That is, while the seal member 34 is insertedin the annular groove 41, a gap g is formed between the seal member 34and at least one of the first side wall 43 and second side wall 44defining the annular groove 41. Moreover, the seal member 34 is formedto have an outer diameter d2 larger than the inner diameter B of the airinjection port 16.

That is, the seal member 34 is inserted into the air injection port 16of the polishing jig 2, together with the main body 33 of the injectionmember 4, thereby pressing it inwards in the radial direction by a wallsurface 16 a of the air injection port 16, as shown in FIG. 4. At thistime, the inner circumferential portion of the seal member 34 is kept incontact with the circumferential wall 42 to prevent the seal member 34from deforming inwards in the radial direction, so the seal member 34elastically deforms toward the gap g. As a result, the gap g is sealedby the elastically deformed seal member 34. In other words, the gap g isformed so as to be sealed by the seal member 34 elastically deformedupon inserting the injection member 4 into the air injection port 16.

Note that the seal member 34 is not limited to an O-ring, and can takeany form as long as it serves as an elastic body having a shape whichextends over the entire circumference along the annular groove 41. Forexample, the seal member 34 can use an elastic body formed in a ringshape, or an elastic body having a shape obtained by cutting a ring inone circumferential portion. When the seal member 34 uses an elasticbody having a ring shape obtained by cutting a ring in onecircumferential portion in this manner, it can be opened in a C shape,thus making it possible to easily perform an operation of inserting itinto the annular groove 41 and an operation of removing it from theannular groove 41.

The elastic body which forms the seal member 34 can be made of amaterial such as fluororubber (FPM). Fluororubber has self-lubricity andtherefore has a resistance which reduces upon inserting/removing theseal member 34 into/from the air injection port 16 of the polishing jig2. This not only facilitates attachment/detachment of the polishing jig2 but also makes it hard for the seal member 34 to wear out.

To inject air into the balloon member 11 of the polishing jig 2 usingthe polishing jig air injection apparatus 1 configured as describedabove, first, the polishing jig 2 is mounted on the installation base 3set at the jig attachment/detachment position, and the injection member4 is inserted into the air injection port 16, as shown in FIG. 4. Atthis time, the attachment surface 12 a of the polishing jig 2 faces theinstallation surface 3 a of the installation base 3. Upon inserting theinjection member 4 into the air injection port 16, the seal member 34 iscompressed and elastically deforms so as to enter the gap g. Even whilethe seal member 34 is compressed in the annular groove 41, itselasticity does not degrade. Therefore, the seal member 34 comes intotight contact with the circumferential wall 42 and first and second sidewalls 43 and 44 defining the annular groove 41, and the wall surface 16a of the air injection port 16, with an appropriate elastic repulsiveforce, thereby sealing the gap between the injection member 4 and theair injection port 16.

Next, the installation base 3 is moved to the height measurementposition, and the air supply device 6 is operated to discharge air intothe air passage 5. The air in the air passage 5 flows into the airinjection port 16 upon passing through the through hole 35 in theinjection member 4. At this time, the seal member 34 remains in tightcontact with the walls 42 to 44 defining the annular groove 41 and thewall surface 16 a of the air injection port 16, so the air does not leakupon passing through the gap between the air injection port 16 and theinjection member 4.

The air supplied into the air injection port 16 flows into the balloonmember 11 upon passing through the valve 15 when the pressure in the airinjection port 16 rises to the degree that the valve 15 opens. Theballoon member 11 inflates upon injecting air into it. The air isinjected into the balloon member 11 until the height of the balloonmember 11 measured by the height measuring device reaches a targetheight. The target height means herein the height corresponding to thecurvature of the surface of a spectacle lens to be polished.

The installation base 3 is returned to the jig attachment/detachmentposition after completion of air injection into the balloon member 11,as described above. After the installation base 3 moves to the jigattachment/detachment position, the polishing jig 2 is detached from theinstallation base 3 and loaded into the polishing apparatus. When thepolishing jig 2 is detached from the installation base 3, a force actson the seal member 34 so as to pull it away from the injection member 4.In fact, however, the seal member 34 does not fall off the injectionmember 4 because it is inserted and held in the annular groove 41.

Hence, since the polishing jig air injection apparatus 1 according tothis embodiment uses a ready-made O-ring as the seal member 34, itsmanufacturing cost can be kept low. Also, since the polishing jig airinjection apparatus 1 according to this embodiment does not degrade inelasticity even while the seal member 34 is compressed in the annulargroove 41, it is possible not only to achieve high seal performance butalso to prevent the seal member 34 from wearing out uponattaching/detaching the polishing jig 2.

Note that high seal performance can be achieved because the seal member34 is pressed against the walls 42 to 44 defining the annular groove 41and the wall surface 16 a of the air injection port 16, with anappropriate elastic repulsive force. That is, the seal performanceimproves because the seal member 34 can deform to follow minuteprojections and recesses formed on and in the surfaces of the walls 42to 44.

The reason why the seal member 34 can be prevented from wearing out isthat it is not pressed against the wall surface 16 a of the airinjection port 16 with too much force, so its frictional resistancerelatively decreases upon sliding it on the wall surface 16 a.

Moreover, since the seal member 34 is inserted in the annular groove 41and does not fall off the injection member 4 in the polishing jig airinjection apparatus 1 according to this embodiment, an operation ofloading the polishing jig 2 from the installation base 3 into thepolishing apparatus after air injection is not interrupted. Therefore,the use of the polishing jig air injection apparatus 1 allows efficientpolishing of the spectacle lens.

Second Embodiment

An injection member and a seal member can be formed, as shown in FIGS. 5and 6. Referring to FIGS. 5 and 6, the same reference numerals denotethe same or equivalent members as or to those described with referenceto FIGS. 1 to 4, and a detailed description thereof will not be given asneeded.

A seal member 34 shown in FIG. 5 is formed to have an outer diameter d2larger than an inner diameter H of an air injection port 16, like theseal member 34 shown in FIGS. 3 and 4. However, the seal member 34 isformed to have a thickness W equal to a groove width (an intervalbetween a first side wall 43 and a second side wall 44) G of an annulargroove 41. Also, the seal member 34 is formed to have an inner diameterd1 larger than an outer diameter D of a circumferential wall 42 definingthe annular groove 41.

That is, in this embodiment, a gap g is formed between thecircumferential wall 42 defining the annular groove 41 and the innercircumferential portion of the seal member 34. Upon inserting the sealmember 34 according to this embodiment into the air injection port 16,it elastically deforms inwards in the radial direction so as to enterthe gap g, as shown in FIG. 6. The seal member 34 thus elasticallydeforms, thereby sealing the gap g.

In the second embodiment as well, because the seal member 34 does notdegrade in elasticity, an effect equivalent to that in theabove-described embodiments can be produced.

Third Embodiment

An injection member and a seal member can be formed, as shown in FIGS. 7and 8. Referring to FIGS. 7 and 8, the same reference numerals denotethe same or equivalent members as or to those described with referenceto FIGS. 1 to 4, and a detailed description thereof will not be given asneeded.

A seal member 34 shown in FIG. 7 is formed to have an outer diameter d2larger than an inner diameter B of an air injection port 16, like theseal member 34 shown in FIGS. 3 and 4. Also, the seal member 34 isformed to have a thickness W smaller than a groove width (an intervalbetween a first side wall 43 and a second side wall 44) G of an annulargroove 41. Moreover, the seal member 34 is formed to have an innerdiameter d1 larger than an outer diameter D of a circumferential wall 42defining the annular groove 41.

That is, in this embodiment, a gap g1 is formed between the seal member34 and at least one of the first and second side walls 43 and 44defining the annular groove 41, and a gap g2 is formed between thecircumferential wall 42 and the inner circumferential portion of theseal member 34. Upon inserting the seal member 34 according to thisembodiment into the air injection port 16, it comes into contact with awall surface 16 a of the air injection port 16 and is pressed not onlytoward the second side wall 44 but also inwards in the radial direction.

As a result, the seal member 34 elastically deforms not only inwards inthe radial direction so as to enter the gap g2 positioned inside in theradial direction, but also in the axial direction so as to enter theother gap g1, as shown in FIG. 8. The seal member 34 thus elasticallydeforms, thereby sealing the gaps g1 and g2.

In the third embodiment as well, because the seal member 34 does notdegrade in elasticity although it is compressed in the annular groove41, an effect equivalent to that in the above-described embodiments canbe produced.

Fourth Embodiment

An embodiment of a polishing jig air injection method according to thepresent invention will be described in detail next with reference toFIGS. 9 to 12.

The air injection method according to this embodiment is performed by apolishing jig air injection apparatus 1 having almost the samearrangement as that according to the first embodiment. However, a sealmember 34 uses a seal member which does not come into contact with afirst side wall 43 defining an annular groove 41 even when itelastically deforms upon inserting an injection member 4 into an airinjection port 16 of a polishing jig 2. Note that in this embodiment, agap g1 is formed between the seal member 34 and at least one of thefirst side wall 43 and a second side wall 44 defining the annular groove41 while the seal member 34 is inserted in the annular groove 41, asshown in FIG. 9.

The polishing jig air injection method according to this embodiment isperformed by connection step S1, air supply step S2, and heightadjustment step S3, as shown in FIG. 12.

Connection step S1 is executed by mounting the polishing jig 2 on aninstallation base 3 set at the jig attachment/detachment position, andinserting the injection member 4 into the air injection port 16, asshown in FIGS. 10 and 11.

In connection step S1, when the injection member 4 is inserted into theair injection port 16, the seal member 34 is pressed toward the secondside wall 44 by friction with a wall surface 16 a of the air injectionport 16 first, as shown in FIG. 10 (axial direction pressing step S4).The seal member 34 is brought into contact with the second side wall 44by the pressing, as shown in FIG. 10.

The wall surface 16 a further extends while the seal member 34 is keptin contact with the second side wall 44 in this way (it moves downwardsin FIG. 10). The wall surface 16 a thus further extends, therebypressing the outer circumferential portion of the seal member 34 in thedirection, in which the wall surface 16 a travels, by friction with thewall surface 16 a, so the portion of the seal member 34, which isopposed to the first side wall 43, is displaced outwards in the radialdirection, as indicated by arrows in FIG. 11 (radial directiondeformation step S5).

After completion of connection step S1, the apparatus assumes a stateshown in FIG. 11. That is, in this state, the seal member 34 comes intocontact with the second side wall 44. Also, a gap g1 is formed betweenthe seal member 34 and the first side wall 43 inserted into the airinjection port 16 first of the pair of side walls 43 and 44. Moreover, agap g2 is formed between a circumferential wall 42 and the innercircumferential portion of the seal member 34.

After connection step S1 is thus completed, the process advances to airsupply step S2. Air supply step S2 is executed while a pressurizing airpassage 51 (see FIG. 11) extending from an air discharge port 36 of theinjection member 4 to the inner circumferential portion of the sealmember 34 is ensured, after completion of connection step S1. Thepressurizing air passage 51 is defined by the gaps g1 and g2, a gapbetween the injection member 4 and a valve 15, and a gap g3 (see FIG.11) between the air injection port 16 and the distal end of theinjection member 4.

In air supply step S2, the installation base 3 is moved to the heightmeasurement position, and an air supply device 6 is operated todischarge air into an air passage 5. The air in the air passage 5 flowsinto the air injection port 16 upon passing through a through hole 35 inthe injection member 4. The air supplied into the air injection port 16flows into a balloon member 11 upon passing through the valve 15 as thepressure in the air injection port 16 rises to the degree that the valve15 opens. The balloon member 11 inflates upon injecting air into it inthis way.

On the other hand, the pressure of the air discharged from the airdischarge port 36 propagates to the inner circumferential portion of theseal member 34 as well via the pressurizing air passage 51. Uponapplying the air pressure to the inner circumferential portion of theseal member 34 in this way, the seal member 34 is pressed outwards inthe radial direction, so the force acting to press the wall surface 16 aof the air injection port 16 increases (pressurization step S6). Thatis, according to this embodiment, the gap between the injection member 4and the air injection port 16 can be sealed by biasing the seal member34 using the air pressure.

The air is injected into the balloon member 11 until the height of theballoon member 11 measured by a height measuring device reaches a targetheight in height adjustment step S3. The target height means herein theheight corresponding to the curvature of the surface of a spectacle lensto be polished.

The installation base 3 is returned to the jig attachment/detachmentposition after completion of air injection into the balloon member 11.After the installation base 3 moves to the jig attachment/detachmentposition, the polishing jig 2 is detached from the installation base 3and loaded into the polishing apparatus.

Hence, according to this embodiment, since the pressurizing air passage51 is ensured before the start of air supply step S2, the air pressurecan reliably be applied to the inner circumferential portion of the sealmember 34 so that the seal member 34 can be biased by the air pressureto perform sealing, despite the use of the inexpensive ready-made sealmember 34.

Therefore, according to this embodiment, it is possible to provide anair supply method for the polishing jig 2, which can keep themanufacturing cost of the polishing jig air injection apparatus 1 lowwhile sustaining high seal performance.

Connection step S1 according to this embodiment includes axial directionpressing step S4 and radial direction deformation step S5. In axialdirection pressing step S4, the seal member 34 is pressed toward thesecond side wall 44 by friction with the wall surface 16 a of the airinjection port 16. In radial direction deformation step S5, the sealmember 34 elastically deforms so that the gap g2 is formed between itand the circumferential wall 42 by friction with the wall surface 16 aof the air injection port 16.

Hence, according to this embodiment, the pressurizing air passage 51 canforcibly be formed by elastically deforming the seal member 34 outwardsin the radial direction using an operation of inserting the injectionmember 4 into the air injection port 16. Therefore, again according tothis embodiment, since the seal member 34 can more reliably expandoutwards in the radial direction, high seal reliability can be attained.

Fifth Embodiment

A pressurizing air passage can be ensured by a method to be describedwith reference to FIGS. 13 to 15.

Referring to FIGS. 13 to 15, the same reference numerals denote the sameor equivalent members as or to those described with reference to FIGS. 9to 12, and a detailed description thereof will not be given as needed.

A seal member 34 shown in FIG. 13 is formed to have an outer diameter d2larger than an inner diameter B of an air injection port 16, like theseal member 34 shown in FIGS. 9 to 11. However, the seal member 34 isformed to have a thickness W equal to a groove width (an intervalbetween a first side wall 43 and a second side wall 44) G of an annulargroove 41. Also, the seal member 34 is formed to have an inner diameterd1 larger than an outer diameter D of a circumferential wall 42 definingthe annular groove 41.

That is, the seal member 34 according to this embodiment comes intocontact with the two side walls 43 and 44 defining the annular groove41, and is formed in a shape in which a gap g2 is formed between it andthe circumferential wall 42. Upon inserting the seal member 34 accordingto this embodiment into the air injection port 16, it is pressed towardan installation base 3 in the axial direction by friction with a wallsurface 16 a of the air injection port 16, as indicated by arrows inFIG. 14.

Hence, the seal member 34 according to this embodiment elasticallydeforms so as to form a gap g1 between it and the first side wall 43 inconnection step S1 in which it is inserted into the air injection port16. That is, connection step S1 according to this embodiment includesaxial direction deformation step S7 (see FIG. 15) in which the sealmember 34 elastically deforms upon being pressed in the axial direction,as described above. In this embodiment as well, upon completion ofconnection step S1, a pressurizing air passage 51 is formed to extendfrom an air discharge port 36 of an injection member 4 to the innercircumferential portion of the seal member 34, as shown in FIG. 14.

Hence, the air injection method for a polishing jig 2 according to thisembodiment can forcibly form the pressurizing air passage 51 byelastically deforming the seal member 34 in the axial direction using anoperation of inserting the injection member 4 into the air injectionport 16. Therefore, according to this embodiment, since the seal member34 can more reliably expand outwards in the radial direction, high sealreliability can be attained.

Sixth Embodiment

A pressurizing air passage can be ensured by a method shown in FIGS. 16to 18.

Referring to FIGS. 16 to 18, the same reference numerals denote the sameor equivalent members as or to those described with reference to FIGS. 9to 12, and a detailed description thereof will not be given as needed.

A seal member 34 shown in FIG. 16 is formed to have an outer diameter d2large enough to bring it into contact with a wall surface 16 a of an airinjection port 16. That is, the outer diameter d2 is set equal to orslightly larger than an inner diameter B of the air injection port 16.Also, the seal member 34 is formed to have a thickness W smaller than agroove width (an interval between a first side wall 43 and a second sidewall 44) G of an annular groove 41. Moreover, the seal member 34 isformed to have an inner diameter d1 larger than an outer diameter D of acircumferential wall 42 defining the annular groove 41.

That is, the seal member 34 according to this embodiment is formed in ashape in which a gap g1 is formed between it and at least one of theside walls 43 and 44 defining the annular groove 41, and a gap g2 isformed between it and the circumferential wall 42.

Upon inserting the seal member 34 according to this embodiment into theair injection port 16, it is pressed toward an installation base 3 inthe axial direction by friction with the wall surface 16 a of the airinjection port 16, as indicated by arrows in FIG. 17.

Hence, the seal member 34 according to this embodiment comes intocontact with the second side wall 44 upon being pressed in theabove-mentioned way in connection step S1 in which it is inserted intothe air injection port 16. That is, connection step S1 according to thisembodiment includes axial direction pressing step S4 (see FIG. 18) inwhich the seal member 34 is pressed in the axial direction, as describedabove. In this embodiment as well, upon completion of connection stepS1, a pressurizing air passage 51 is formed to extend from an airdischarge port 36 of an injection member 4 to the inner circumferentialportion of the seal member 34.

The air injection method for a polishing jig 2 according to thisembodiment can form the pressurizing air passage 51 without considerablyelastically deforming the seal member 34. Therefore, according to thisembodiment, since air supply step S2 starts while the seal member 34 haselastically deformed by a relatively small amount, the seal member 34can be sufficiently elastically deformed using the air pressure. As aresult, the adoption of the air injection method according to thisembodiment allows a further improvement in seal performance.

When a prototype was manufactured for the injection member 4 shown inthis embodiment to have dimensions shown in FIG. 19, and air wasinjected into the polishing jig 2 in practice, the injection member 4could be repeatedly used without leakage of the air or fall of the sealmember 34. A main body 33 of the injection member 4 used in thisexperiment has an outer diameter A of 12.6 mm, the circumferential wall42 defining the annular groove 41 has an outer diameter D of 7.2 mm, andthe annular groove 41 has a groove width G is 3.7 mm. The seal member 34has an inner diameter d1 of 7.5 mm and a thickness W of 3.55 mm.Accordingly, the seal member 34 has an outer diameter of 14.6 mm. AnO-ring named AS568-203 was used as the seal member 34. This O-ring ismade of fluororubber (FPM).

This experiment was conducted using a plurality of polishing jigs 2 tobe used for polishing in practice by repeating attachment/detachment ofeach polishing jig 2 100 times and air injection 100 times. During theexperiment, it was checked whether the seal member 34 had fallen uponattaching/detaching each polishing jig 2, and it was checked whether airhad leaked upon injecting air into the polishing jig 2. The experimentalresults were evaluated upon determining that attachment/detachment issatisfactory when each polishing jig 2 could be attached/detached 95 ormore times without fall of the seal member 34, and that air injection issatisfactory when air could be injected into the polishing jig 2 95 ormore times without leakage of the air.

As the experimental results, satisfactory was determined for all thepolishing jigs 2 with regard to both polishing jig attachment/detachmentand air injection, as shown in Table 1. In Table 1, “good” indicatessatisfactory results for each polishing jig 2. Sizes A and B of eachpolishing jig 2 shown in Table 1 have values obtained by measuring theinner diameter B of the air injection port 16 in two orthogonaldirections. The air injection ports 16 of the polishing jigs 2 used inthis experiment have inner diameters B of 14.0 to 14.32 mm, as can beseen from Table 1. The size of the air injection port 16 varies in eachindividual polishing jig 2 because it has a given tolerance.

TABLE 1 Size A Size B Polishing Jig (mm) (mm) Attachment/Detachment AirInjection 1 14.04 14.01 Good Good 2 14.11 14.32 Good Good 3 14.07 14.14Good Good 4 14.02 14.01 Good Good 5 14.09 14.08 Good Good 6 14.04 14.03Good Good 7 14.10 14.07 Good Good 8 14.05 14.07 Good Good 9 14.06 14.06Good Good 10 14.06 14.05 Good Good 11 14.07 14.08 Good Good 12 14.1014.12 Good Good 13 14.08 14.03 Good Good 14 14.03 14.00 Good Good 1514.04 14.03 Good Good 16 14.15 14.07 Good Good 17 14.08 14.07 Good Good18 14.04 14.10 Good Good

The effects of the embodiments described above are compared with theprior art. The prior art used an apparatus including a seal memberhaving a special shape, as indicated in literature 1. Table 2 summarizesthe results obtained when air injections were repeated 100 times/day(3,000 times/month) for the prior art and the embodiments describedabove.

Since the seal member of the prior art was of a cover type, it was oftenremoved from the injection member when the polishing jig was attached ordetached. When the air injections were repeated 100 times/day, the sealmember was removed about 5 times/day. To the contrary, since each of theembodiments employs a fitting type seal member, it cannot be easilyremoved. The removal frequency of the seal member 34 was about once/daydepending on the shape and type of the polishing jig 2 when airinjections were repeated for the embodiments under the same conditionsas in the prior art. The operation error frequency of about 5% in theprior art was reduced to about 1% in the embodiments described above.The air injection can thus be improved by the embodiments describedabove.

The prior art required seal member replacement every time the airinjections were repeated 1,500 times. To the contrary, in eachembodiment described above, the seal member 34 can stand repeatedinjections as many as 6,000 times. The prior art required seal memberreplacement of twice/month, and each embodiment required seal memberreplacement of 0.5 times/month when the air injections were repeated3,000 times per month.

The seal member used in the prior art was a dedicated component having aspecial shape, which was expensive. To the contrary, each embodimentdescribed above can use a general-purpose O-ring as the seal member 34,thereby reducing the cost of the seal member. In consideration of thereplacement frequency of the seal members, the running cost can begreatly reduced in each embodiment.

The seal member 34 of each embodiment described above could maintain thesame durability as in the prior art.

TABLE 2 Item Prior Art Embodiments Frequency of about 5% about 1%Injection Error Operability unsatisfactory good Replacement about aboutFrequency 2 times/month 0.5 times/month Durability good good Cost (unitcost) ¥3,590/pcs ¥200/pcs Running Cost ¥7,180/month ¥100/month(estimated) Others finished product general-purpose O-ring

Although an example in which an O-ring having a circular cross-sectionis used as the seal member 34 has been given in each of theabove-described embodiments, the cross-sectional shape of the sealmember 34 can appropriately be changed to, for example, an elliptical oroval shape.

According to the first to third embodiments mentioned above, the sealmember 34 is compressed so as to enter the gap g formed between it andthe annular groove 41 by inserting it into the air injection port 16,together with the main body 33 of the injection member 4. Since the sealmember 34 does not degrade in elasticity even while it is compressed inthe annular groove 41, it reliably seals the gap between the annulargroove 41 and the air injection port 16. Also, since the seal member 34is inserted in the annular groove 41 in the injection member 4, it doesnot easily fall off the injection member 4. Moreover, the seal member 34can use an inexpensive ready-made product. Therefore, it is possible toprovide the polishing jig air injection apparatus 1 including the sealmember 34 which has high seal performance, and does not easily fall offthe injection member 4, but nonetheless is inexpensive.

According to the fourth to sixth embodiments mentioned above, the airdirectly flows into the air injection port 16 from the air dischargeport 36 of the injection member 4. Since the seal member 34 is formedfrom an annular elastic body extending along the annular groove 41, itcan use an inexpensive ready-made product. Also, according to the airinjection method, after completion of connection step S1, that is,before the start of air supply step S2, the pressurizing air passage 51extending from the air discharge port 36 of the injection member 4 tothe inner circumferential portion of the seal member 34 can be ensured.Therefore, the air pressure can reliably be applied to the innercircumferential portion of the seal member 34 so that the seal member 34can be biased by the air pressure to perform sealing, despite the use ofthe inexpensive ready-made seal member 34. Therefore, it is possible toprovide an air supply method for a polishing jig, which can keep themanufacturing cost of a polishing jig air injection apparatus low whilesustaining high seal performance.

1. A polishing jig air injection apparatus comprising: a polishing jiginstallation base including an installation surface on which a spectaclelens polishing jig including an air injection port and a balloon memberwhich inflates by a pressure of air supplied from the air injection portis placed; an injection member which is supported on said installationsurface of said polishing jig installation base while projecting fromsaid installation surface, and inserted into the air injection port ofthe spectacle lens polishing jig; and an air supply device which isconnected to said injection member and supplies the air into the balloonmember via said injection member and the air injection port, saidinjection member including a main body formed in a pillar shape, saidmain body including an air passage extending through two ends of saidmain body, and an annular groove formed in an outer circumferentialportion of said main body, and a seal member which is inserted into saidannular groove, is formed in an annular shape that extends over anentire circumference along said annular groove, and uses an elasticbody, said seal member having an outer diameter larger than an innerdiameter of the air injection port.
 2. An apparatus according to claim1, wherein said seal member is formed from an O-ring.
 3. An apparatusaccording to claim 1, wherein the air injection port opens on anattachment surface of the spectacle lens polishing jig, which is opposedto said installation surface of said polishing jig installation base,and has a circular shape defined in the attachment surface, said mainbody of said injection member has a columnar shape, and said seal memberof said injection member has an annular shape.
 4. An apparatus accordingto claim 1, wherein a gap to be sealed by said seal member elasticallydeformed upon inserting said injection member into the air injectionport is present between said seal member and said annular groove.
 5. Anapparatus according to claim 4, wherein said annular groove includes acircumferential wall parallel to an outer circumferential surface ofsaid main body, and a pair of side walls extending outwards in a radialdirection from said circumferential wall, and the gap is present betweensaid seal member and at least one of said pair of side walls.
 6. Anapparatus according to claim 4, wherein said annular groove includes acircumferential wall parallel to an outer circumferential surface ofsaid main body, and a pair of side walls extending outwards in a radialdirection from said circumferential wall, and the gap is present betweensaid seal member and said circumferential wall.
 7. A polishing jig airinjection method comprising the steps of: inserting an injection memberinto an air injection port of a spectacle lens polishing jig; anddischarging air from the injection member into the air injection port toinflate a balloon member connected to the air injection port, theinjection member including a main body formed in a pillar shape, themain body including an air passage extending through two ends of themain body, and an annular groove formed in an outer circumferentialportion of the main body, and a seal member which is inserted into theannular groove, is formed in an annular shape that extends over anentire circumferential region along the annular groove, and uses anelastic body, the seal member (34) having an outer diameter larger thanan inner diameter of the air injection port.
 8. A method according toclaim 7, wherein the annular groove includes a circumferential wallparallel to an outer circumferential surface of the main body, and apair of side walls extending outwards in a radial direction from thecircumferential wall, the inserting step includes the step of forming agap between the seal member and the circumferential wall, forming a gapbetween the seal member and one side wall inserted into the airinjection port first of the pair of side walls, and bringing the sealmember into contact with the other side wall of the pair of side walls,and the discharging step includes the step of biasing the seal memberoutwards in a radial direction by a pressure of air to press an outercircumferential portion of the seal member against a wall surface of theair injection port.
 9. A method according to claim 8, wherein the sealmember is formed in a shape, in which the seal member comes into contactwith the circumferential wall defining the annular groove, and the gapis formed between the seal member and at least one of the pair of sidewalls defining the annular groove, and the inserting step includes thesteps of pressing the seal member toward said other side wall byfriction between the seal member and the wall surface of the airinjection port, and elastically deforming the seal member so that thegap is formed between the seal member and the circumferential wall byfriction between the seal member and the wall surface of the airinjection port.
 10. A method according to claim 8, wherein the sealmember is formed in a shape, in which the seal member comes into contactwith both the pair of side walls defining the annular groove, and thegap is formed between the seal member and the circumferential walldefining the annular groove, and the inserting step includes the step ofelastically deforming the seal member so that the gap is formed betweenthe seal member and said one side wall by friction between the sealmember and the wall surface of the air injection port.
 11. A methodaccording to claim 8, wherein the seal member is formed in a shape inwhich the gaps are formed between the seal member and at least one ofthe pair of side walls defining the annular groove, and between the sealmember and the circumferential wall defining the annular groove, and theinserting step includes the step of pressing the seal member toward saidother side wall by friction between the seal member and the wall surfaceof the air injection port.